Resonance Raman spectroscopy of osmium prophyrins will provide evidence for the electron-density induced frequency shifts in the oxidation state marker bands of hemoproteins and charge-transfer transitions in the visible and Soret region. "Tail" aromatic-linked prophyrins are being synthesized to examine the MCD, redox, and resonance Raman properties of low-spin iron (IV) and iron (IV) II-cations to ascertain if these oxidation states are present in the oxidized forms of peroxidase. The semi-empirical Xalpha theory is used for understanding the mechanism ofresonant Raman enhancement in charge transfer complexes and will be extended to transition metal complexes.